The FBI is supposed to be the nation’s elite law-enforcement agency. Its agents protect us from terrorist attack, combat public corruption and fight organized crime. It’s supposed to be on top of its game.

But when it comes to the simple act of paying its telephone bills – well, not so much.

A recent Justice Department audit found the agency repeatedly failed to pay its phone bills on time, resulting in some FBI wiretaps – used to spy on suspected criminals – being cut off.

Our first instinct is to laugh, but what an embarrassment. How can the American people trust the agency to protect the country against sophisticated threats when it can’t be relied upon to pay its bills?

It appears, according to the audit, that the agency didn’t properly oversee the money used in undercover investigations. Of the 990 bills for telecommunication surveillance, more than half weren’t paid on time, including a tab of $66,000 at an FBI field office that was not identified by auditors.

In one instance, a wiretap authorized under the Foreign Intelligence Surveillance Act (FISA), which is used to investigate acts of terrorism, was cut off.

And at that point, you stop laughing. That’s serious business.

FBI officials said that in every case mentioned in the audit, information was recovered after the delinquent bills were paid. It makes us wonder about instances that perhaps weren’t mentioned in the audit.

The late payments were part of a larger pattern of loose practices when it comes to tracking money sent to field offices for undercover operations.

It’s one of several scandals the agency has endured in recent years. A 2002 audit showed hundreds of guns and laptops could not be accounted for. Last year, the Justice Department’s inspector general told members of Congress the FBI may have violated policy or law more than 3,000 times as it collected telephone, bank and credit card records using national security letters. (The letters are essentially administrative subpoenas that can be issued by the agency without court review.)

In the coming weeks, Congress will debate the reauthorization of FISA, which gives the FBI and other agencies unprecedented latitude to spy on communications without oversight. The so-called FISA updates sunset Feb. 1, and that’s probably a good thing. The changes were billed as revisions to keep with up the digital age, but in reality gave the administration broad new powers to spy without getting a warrant, even a secret one through FISA.

It’s difficult to justify entrusting more power to what are supposed to be the country’s top-flight investigators when the agency fails to carry out basic functions such as paying its bills.